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1/*
2 * cpuidle.h - a generic framework for CPU idle power management
3 *
4 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
5 * Shaohua Li <shaohua.li@intel.com>
6 * Adam Belay <abelay@novell.com>
7 *
8 * This code is licenced under the GPL.
9 */
10
11#ifndef _LINUX_CPUIDLE_H
12#define _LINUX_CPUIDLE_H
13
14#include <linux/percpu.h>
15#include <linux/list.h>
16#include <linux/hrtimer.h>
17
18#define CPUIDLE_STATE_MAX 10
19#define CPUIDLE_NAME_LEN 16
20#define CPUIDLE_DESC_LEN 32
21
22struct module;
23
24struct cpuidle_device;
25struct cpuidle_driver;
26
27
28/****************************
29 * CPUIDLE DEVICE INTERFACE *
30 ****************************/
31
32struct cpuidle_state_usage {
33 unsigned long long disable;
34 unsigned long long usage;
35 unsigned long long time; /* in US */
36};
37
38struct cpuidle_state {
39 char name[CPUIDLE_NAME_LEN];
40 char desc[CPUIDLE_DESC_LEN];
41
42 unsigned int flags;
43 unsigned int exit_latency; /* in US */
44 int power_usage; /* in mW */
45 unsigned int target_residency; /* in US */
46 bool disabled; /* disabled on all CPUs */
47
48 int (*enter) (struct cpuidle_device *dev,
49 struct cpuidle_driver *drv,
50 int index);
51
52 int (*enter_dead) (struct cpuidle_device *dev, int index);
53};
54
55/* Idle State Flags */
56#define CPUIDLE_FLAG_COUPLED (0x02) /* state applies to multiple cpus */
57#define CPUIDLE_FLAG_TIMER_STOP (0x04) /* timer is stopped on this state */
58
59#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
60
61struct cpuidle_device_kobj;
62struct cpuidle_state_kobj;
63struct cpuidle_driver_kobj;
64
65struct cpuidle_device {
66 unsigned int registered:1;
67 unsigned int enabled:1;
68 unsigned int cpu;
69
70 int last_residency;
71 int state_count;
72 struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
73 struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
74 struct cpuidle_driver_kobj *kobj_driver;
75 struct cpuidle_device_kobj *kobj_dev;
76 struct list_head device_list;
77
78#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
79 int safe_state_index;
80 cpumask_t coupled_cpus;
81 struct cpuidle_coupled *coupled;
82#endif
83};
84
85DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
86DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);
87
88/**
89 * cpuidle_get_last_residency - retrieves the last state's residency time
90 * @dev: the target CPU
91 */
92static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
93{
94 return dev->last_residency;
95}
96
97
98/****************************
99 * CPUIDLE DRIVER INTERFACE *
100 ****************************/
101
102struct cpuidle_driver {
103 const char *name;
104 struct module *owner;
105 int refcnt;
106
107 /* used by the cpuidle framework to setup the broadcast timer */
108 unsigned int bctimer:1;
109 /* states array must be ordered in decreasing power consumption */
110 struct cpuidle_state states[CPUIDLE_STATE_MAX];
111 int state_count;
112 int safe_state_index;
113
114 /* the driver handles the cpus in cpumask */
115 struct cpumask *cpumask;
116};
117
118#ifdef CONFIG_CPU_IDLE
119extern void disable_cpuidle(void);
120
121extern int cpuidle_select(struct cpuidle_driver *drv,
122 struct cpuidle_device *dev);
123extern int cpuidle_enter(struct cpuidle_driver *drv,
124 struct cpuidle_device *dev, int index);
125extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
126
127extern int cpuidle_register_driver(struct cpuidle_driver *drv);
128extern struct cpuidle_driver *cpuidle_get_driver(void);
129extern struct cpuidle_driver *cpuidle_driver_ref(void);
130extern void cpuidle_driver_unref(void);
131extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
132extern int cpuidle_register_device(struct cpuidle_device *dev);
133extern void cpuidle_unregister_device(struct cpuidle_device *dev);
134extern int cpuidle_register(struct cpuidle_driver *drv,
135 const struct cpumask *const coupled_cpus);
136extern void cpuidle_unregister(struct cpuidle_driver *drv);
137extern void cpuidle_pause_and_lock(void);
138extern void cpuidle_resume_and_unlock(void);
139extern void cpuidle_pause(void);
140extern void cpuidle_resume(void);
141extern int cpuidle_enable_device(struct cpuidle_device *dev);
142extern void cpuidle_disable_device(struct cpuidle_device *dev);
143extern int cpuidle_play_dead(void);
144extern void cpuidle_use_deepest_state(bool enable);
145
146extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
147#else
148static inline void disable_cpuidle(void) { }
149static inline int cpuidle_select(struct cpuidle_driver *drv,
150 struct cpuidle_device *dev)
151{return -ENODEV; }
152static inline int cpuidle_enter(struct cpuidle_driver *drv,
153 struct cpuidle_device *dev, int index)
154{return -ENODEV; }
155static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
156static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
157{return -ENODEV; }
158static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
159static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
160static inline void cpuidle_driver_unref(void) {}
161static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
162static inline int cpuidle_register_device(struct cpuidle_device *dev)
163{return -ENODEV; }
164static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
165static inline int cpuidle_register(struct cpuidle_driver *drv,
166 const struct cpumask *const coupled_cpus)
167{return -ENODEV; }
168static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
169static inline void cpuidle_pause_and_lock(void) { }
170static inline void cpuidle_resume_and_unlock(void) { }
171static inline void cpuidle_pause(void) { }
172static inline void cpuidle_resume(void) { }
173static inline int cpuidle_enable_device(struct cpuidle_device *dev)
174{return -ENODEV; }
175static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
176static inline int cpuidle_play_dead(void) {return -ENODEV; }
177static inline void cpuidle_use_deepest_state(bool enable) {}
178static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
179 struct cpuidle_device *dev) {return NULL; }
180#endif
181
182#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
183void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
184#else
185static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
186{
187}
188#endif
189
190/******************************
191 * CPUIDLE GOVERNOR INTERFACE *
192 ******************************/
193
194struct cpuidle_governor {
195 char name[CPUIDLE_NAME_LEN];
196 struct list_head governor_list;
197 unsigned int rating;
198
199 int (*enable) (struct cpuidle_driver *drv,
200 struct cpuidle_device *dev);
201 void (*disable) (struct cpuidle_driver *drv,
202 struct cpuidle_device *dev);
203
204 int (*select) (struct cpuidle_driver *drv,
205 struct cpuidle_device *dev);
206 void (*reflect) (struct cpuidle_device *dev, int index);
207
208 struct module *owner;
209};
210
211#ifdef CONFIG_CPU_IDLE
212extern int cpuidle_register_governor(struct cpuidle_governor *gov);
213#else
214static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
215{return 0;}
216#endif
217
218#ifdef CONFIG_ARCH_HAS_CPU_RELAX
219#define CPUIDLE_DRIVER_STATE_START 1
220#else
221#define CPUIDLE_DRIVER_STATE_START 0
222#endif
223
224#endif /* _LINUX_CPUIDLE_H */